Field of the Invention
Fireproofing.
Description of the Prior Art
The prior art teaches a number of phosphorus-nitrogen compounds as flame retardants for various textile materials. Many of these known flame retardants are also treated with formaldehyde or trimethylolamine and a catalyst to give permanence to the bond of the phosphorus-nitrogen compound to the textile material against removal by washing; otherwise, much of the flame retardant property is lost as the material is periodically cleaned by detergent washing. The phosphorus-nitrogen compound of this invention apparently does not require this formaldehyde or the like treatment to be resistant to removal from the textile by detergent washing.
One of the older patents in this art is U.S. Pat. No. 2,782,133 teaching aminocyclophosphazene as a fireproofing agent for cellulosic fibers such as cotton. A recent patent is U.S. Pat. No. 3,711,542 teaching certain new N-methylol phosphazene compounds as flame retardants on cotton, and this patent under Background of the Invention contains a summary of certain phosphazene prior art on flameproofing.